Untitled Flashcards Set
Standardizaiton
The process of determining the concentration of a solution
Standard Solution
Once the concentration of the solution is known
Primary Standard
Any compound that is stable, pure, and completely reacts with known stoichiometry with the solution being standardized
Neutralization Reaction
A reaction between an acid and a base
Monoprotic Acid
One dissociable proton
Diprotic Acid
Two dissociable protons
Titration
A technique of accurately measuring the volume of a solution required to react with another reagent
Indicators
Tell when a titration is complete
Protonated Form
The form of an indicator (or anything) where the proton is attached
Deprotonated Form
The form of an indicator (or anything) where the proton is off of it
Endpoint
When the indicator changes color
Equivalence Point
The point where the number of equivalents in the two reactants are physically equal
Chromatography
A process that permits the separation of a mixture into its components as a result of differences in rates at which the individual components of the mixture migrate through a stationary medium under the influence of a mobile phase
Mobile Phase
Acts as a carrier gas (hydrogen)
Stationary Phase
Acts as a stationary phase (capillary column that has a polymer coated on the inside)
Injector
Injects the sample into the column
Migration
Movement of molecules back and forth between two phases
Ts
The time a molecule spends attracted to the stationary phase
Tm
The time a molecule spends with the mobile phase
Eluting
When components come off the column
Gas Chromatograph
Keeps track of how long it takes from when the sample was injected onto the column to when it comes off of the column into the detector
Retention Time
The amount of time between when a sample is injected onto the column and when it comes off of the column (characteristic for each compound)
Intermolecular Forces
The forces that exist between the molecules of a compound
Non-Polar Bond
Electrons are shared equally between atoms
Non-Polar Molecule
There are no charges on the opposite ends of the molecule, or the charges have the same sign
Polar Bond (Covalent)
One atom exerts a greater attraction for the electrons than the other
Ionic Bond
Formed when one atom gives up one or more electrons to another atom
Polar Molecule
When a molecules center of negative and positive charge to not coincide
Dipole Moment
The extent of the charge separation on a polar molecule
Polarizable
The ease at which a non-polar molecules electron cloud is distorted to set up a dipole
Ion-Dipole Force
- Exist between an ion and the partial charge on the end of a polar molecule
- Very strong (40-60)
Dipole-Dipole Force
- Exist between neutral polar molecules
- Effective when molecules come very close to each other
- 5-25 kJ/mol
Hydrogen Bonding
- Special type of dipole-dipole
- Exist between hydrogen atom and an unshared pair of electrons
- 20-60 kJ/mol
London-Dispersion Force
- Occur when two non-polar molecules approach each other and distort their electron clouds
- Electron clouds temporarily redistribute
- Strength depends on polarizability (0.05-40)
Viscosity
A measure of the fluids resistance to flow
Covalent Bond
- Have an equal sharing of electrons
- Form a non-polar molecule
Polar Covalent Bond
- Have an unequal sharing of electrons
- Form a polar covalent molecule
Ionic Bond
- Total unequal sharing of electrons
- Forms an ionic molecule
Solution
A homogenous mixture of two or more substances
Saturated Solution
Contains the maximum amount of solute that can dissolve in the volume of solvent at that temperature
Unsaturated Solution
Contains less than the maximum amount of solute that can dissolve in the volume of solvent at that temperature
Supersaturated Solution
Any solution that contains more than the maximum amount of solute dissolved in the volume of solvent at that temperature
Solubility
Known by watching the solid disappear into the liquid
Slightly Soluble
Looks like it hasn't really dissolved at all
Miscibility
Known by watching the liquid disappear into the other liquid
Miscible
Very soluble in solvent
Partially Miscible
Partially soluble in solvent (two layers are seen, but some of the bottom liquid went into the top liquid)
Immiscible
Insoluble in liquid solvent
Solvent
The major component of a solution
Solute
The minor component of a solution
Colligative Properties
Physical properties that depend on a solute concentration
Freezing Point Depression
The difference in freezing point of a liquid when a solute is added
Boiling Point Depression
The difference in boiling point of a liquid when a solute is added
Non-electrolyte
Remains as a molecule in a solution and does not dissociate
Chemical Kinetics
Deals with how fast chemical reactions occur
Catalyst
Increases activation energy of a reaction
Inhibitor
Decreases the activation energy of a reaction
Collision Theory
Particles (molecules) must collide at the proper bond angle and with the proper amount of speed for them to go from reactants to products
Light Source (colorimeter)
Produces light with a wavelength range of 375-900 nm
Monochromator (colorimeter)
Selects a particular wavelength of light and sends it out to the sample sell with an intensity of Io
Sample Cell (colorimeter)
- Contains the solution being analyzed
- Cuvette
Detector (colorimeter)
A phototube and measures the intensity, I, of the light transmitted from the sample cell
Meter (colorimeter)
- Indicates the intensity of the transmitted light
% Transmittance
Corresponds to the percent of light being transmitted through the sample
Absorbance
Computer calculates from %T
Beer's Law
For a given substance, the amount of light absorbed depends upon concentration, cell path length, wavelength, and the solvent
Instantaneous Rate
The rate at a particular time
Half Life
The time required for the concentration of a reactant to decrease to half of its initial concentration
Equilibrium
No change in amounts of products or reactants in a reaction
La Chatelier's Principle
When some stress is applied to a system at equilibrium, the system will shift in a direction to relieve the stress and establish a new state of equilibrium
Stress
Refers to changes in concentration, temperature, or pressure
Heterogeneous Equilibria
- A surface or phase boundary separates the components
- Solid at equilibrium with its ions
Homogeneous Equilibria
Reactants and products are all in the same phase
pH Meter
An instrument used to measure pH
Amplifier (pH Meter)
Makes the voltage output measurable
Calibrated (Digital) Meter (pH Meter)
Shows your pH readings
Bronsted - Lowery Acid Base Theory
The strength of an acid is related to its ability to donate a proton
Acid Dissociation Constant
A measure of the strength of an acid
1st Equivalence Point of Diprotic Acid
H2A -> H+ + HA
2nd Equivalence Point of Diprotic Acid
HA -> H+ + A-
Buffers
Aqueous solutions which resist changes in pH upon the addition of small amounts of an acid or base
Henderson - Hasselbach Equation
Used to calculate the pH of buffer solutions
Buffer Capacity
The number of moles of acid or base required to change the pH of one L of buffer by one pH unit
Solubility Product Constant
The equilibrium constant for the equilibirum between an ionic solid and its saturated solution
Solubility
Of a substance is the quantity that dissolves to form a saturated solution
Molar Solubility
The number of moles of the solute that dissolves in forming a liter of saturated solution
Ion Combination Reaction
Occurs when mixing two aqueous solutions and a precipitate, gas, or weak or non-electrolyte is formed
Spontaneous Reaction
A reaction that occurs under a given set of conditions without help
1st Law of Thermodynamics
Energy is neither created nor destroyed
Entropy
Spontaneity is associated with an increase in randomness or disorder of a system
Gibbs Free Energy
- The free energy change associated with a chemical reaction is a measure of the driving force or spontaneity of the processSol
- Can be calculated at a standard state or not
Electrochemistry
The area of chemistry that deals with the relationship between chemical changes and electrical energy
Voltaic Cell
A cell where chemical reactions produce electrical energy
Electrolytic Cell
Cells where energy is used to bring about chemical changes
Salt Bridge
The ion conducting medium used to physically and chemically separate two half-cells in an electrochemical cell
Anode
Where oxidation occurs
Cathode
Where reduction occurs
Cell potential
The measure of the thermodynamic tendency for the reaction to occur
Solution
A homogenous mixture of two or more substances
Miscible
When two liquids are completely soluble in each other in all proportions
Solute
The substance rpesent in the smaller amount in a solution
Supersatured
A solution that contains more of the solute than is present in a saturated solution
Like Dissolves Like
Means a substance has a type of bonding similar in magnitude to that of a solvent making it a good possibility that the substance will dissolve in the solvent
Solubility
The amount of solute that can dissolve in a given quantity of solvent at a specific temperature. Usually has units of g/100mL
Endothermic
The solute-solvent attraction is weaker than the solute-solute and solvent-solvent attraction. There the solution process needs to take in heat
Unsaturated
A solution that contains less solute than it has the capacity to dissolve